Man Made Object (Ring)

Porphyritic Rhyolite (Red Porp)

Porphyritic Rhyolite (Felsic volcanic rock)

Quartz (Variety: Citrine or Tumbled Chalcedony)

Silicon Dioxide (SiO2)

Quartzite Pebble (River Rock)

Quartzite (primarily SiO2)

Grooved Maun Ball (Maul/Hammerstone-like Concretion)

Calcareous/Ferruginous Concretion in Sandstone Matrix

Chert (Holey Stone)

Microcrystalline Quartz (SiO2)

Granitic Gneiss

Gneiss (High-grade Metamorphic Rock)

Sandstone

Arenite (general term for sandstone)

Quartz

Silicon Dioxide (SiO2)

Rose Quartz

Quartz (SiO₂), specifically a variety of Quartz

Shale

Fissile mudrock (composed of clay-sized particles and detrital grains)

Milky Quartz Pebble (Iron-stained)

Silicon Dioxide (SiO2)

Citrine Quartz

Silicon Dioxide (SiO2) with iron impurities

Ferruginous Quartz (Iron-stained Quartz)

Quartz with Iron Oxide inclusions (SiO2 with Fe2O3)

Chert / Flint

Cryptocrystalline Quartz (SiO2)

Jasper (Red Jasper with Quartz veins)

Jasper (Silicon Dioxide, SiO2)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone

Arenite (primarily Quartz, SiO2)

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Moqui Marble

Iron Oxide Concretion (Limonite/Hematite shell with Sandstone core)

Diabase (also known as Dolerite)

Diabase / Microgabbro

Green Fluorite

Calcium Fluoride (CaF2)

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Amber

Succinite (Fossilized Tree Resin)

Emerald

Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities

Quartz (Clear / Rock Crystal)

Silicon Dioxide (SiO2)

Hypersthene (or Enstatite/Ferrosilite)

Orthopyroxene series (Mg,Fe)SiO3 - specifically, historically hypersthene (intermediate member) now referred to as Enstatite (Mg-rich) or Ferrosilite (Fe-rich)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Serpentinite

Serpentinite ((Mg,Fe,Ni,Al)3Si2O5(OH)4)

Peridotite (Olivine/Peridot)

Peridotite: (Mg,Fe)2SiO4 (Olivine-rich ultramafic rock)

Pink Granite

Phaneritic Felsic Intrusive Igneous Rock

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily SiO2)

Banded Iron Formation (BIF) / Tiger Iron

Ferruginous Chert (primarily Quartz [SiO2] and Hematite/Magnetite [Fe2O3/Fe3O4])

Red Quartzite Cobble

Quartzite (primarily SiO2)

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Hematite (Iron Ore)

Hematite (Fe2O3)

Chert (and its variety Flint)

Silicon Dioxide (SiO2) - Microcrystalline or cryptocrystalline Quartz

Chert (variations include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Prehnite

Prehnite (Ca2Al2Si3O10(OH)2)

Granite with Epidote

Granite, containing quartz, feldspar, and epidote

Fluorite (translucent octahedral crystal)

Calcium fluoride (CaF2)